Holiday Salad

3 heads Bibb or butter lettuce
2 avocados, sliced
1 can mandarin oranges
1 red onion
Blue or feta cheese, crumbled

Dressing
1/2 cup sugar
1 teaspoon dry mustard
1 teaspoon salt
3 tablespoons lemon juice
1/3 cup tarragon vinegar
1 cup oil

Combine salad ingredients, wprinkle with cheese. Toss with dressing.